Abstract：In the direction of arrival (DOA) estimation, the direction finding accuracy depends on the phase consistency between the array elements in the array, so a millimeter-wave four-element linear array with high phase consistency is designed. The antenna is printed on a single-layer substrate, and coaxial probes are used to differentially feed the top patch. Firstly, the coupled feeding method is used to reduce the coupling between the coaxial feeding ports, so as to reduce the phase fluctuation of each array element in the far field. Secondly, the substrate integrated waveguide (SIW) technique is used to reduce the interactions between the array elements and to improve the phase consistency of the array. The simulation results show that the |Sdd11|<-10 dB bandwidth of the linear array is 22.9~25.1 GHz, the maximum gain and isolation of each element in this working band are more than 6.5 dBi and 16.2 dB, respectively. The phase consistency of this array at 23 GHz and 24 GHz in the E-plane, H-plane and ±45°-plane are within ±10°. The antenna is processed and tested, and the experimental and simulation results are in good agreement.

Abstract：In response to the increasing demand for higher operating requencies of millimeter-wave RF transceiver front-ends, this paper presents the design of a V-band millimeter-wave RF transceiver front-end for the reception and transmission of RF signals in the V-band. The RF transceiver front-end circuit is complex, which includes receiver circuits, transmitter circuits, frequency source circuits, power processing circuits and control circuits, with the advantage of multifunctionality, high image rejection, low noise figure, and high transmit power. In order to achieve excellent electrical performance, the front-and design incorporates kinds of microstrip circuirs such as V-band microstrip filters, V-band microstrip power dividers, and V-band quarter-wavelength short-circuit lines. The front-end also utilizes V-band MMIC hybrid multifunctional integration technology, making it suitable for use in guidance head radar and communication scenarios with broad application prospects.

Abstract：According to the communication requirements of the satellite S-band Tracking, Telemetry and Command system (TT&C), a conical Archimedean spiral antenna with wideband and high gain circular polarization is designed for the S-band. The quarter-wavelength coaxial slotted balun completes the balance-unbalance conversion of the signal and wideband impedance matching. The dual-arm Archimedean antenna can provide good circular polarization characteristics, and the FR4 material as a cone not only provides support for the antenna, but also effectively achieves the control of gain and beamwidth. The measured antenna has a Voltage Standing Wave Ratio (VSWR) of less than 1.5, a gain of more than 0 dBi within ±70° and an axial ratio of less than 5 dB in the transceiver frequency band, which can effectively realize the transceiver multiplexing function of the TT&C antenna.

Abstract：Aiming at the development requirements of 5G small base station project, based on the theoretical research of 5G communication system and the requirements of 3GPP RF performance indicators, a 3.5 GHz RF front-end is designed and developed by Advanced Design System（ADS）simulation software. According to the whole development process of RF front-end, this paper conducts in-depth research and evaluation on the performance parameters of key RF components such as power amplifier, low noise amplifier, RF switch and filter, and puts forward the corresponding schematic design, system link simulation and optimization of board and end test indicators. Finally, the actual test of board and end performance indicators is passed. All the index data meet the technical requirements.

Abstract：To meet the requirements of large instantaneous operating bandwidth and simultaneous multi-beams of the satellite-borne Ka-band phased array antenna, a wideband analog multi-beam phased array antenna based on intra-subarray phase shift and inter-subarray delay is designed. The designed 28×28 unit array is divided into four subarray structures, with phase shifters used for each unit within the subarrays and delay lines used between the subarrays. This combined control scheme of phase shifters and delay lines can achieve wide-band and wide-angle scanning of phased array antennas. The simulated results show that, at an instantaneous operating bandwidth of 800 MHz and a scanning angle of ± 54°, the pointing accuracy deviation of the proposed antenna is no more than 0.4°, and the gain deterioration is no more than 0.5 dB. At the same time, the Antenna-in-Package (AiP) architecture is used to achieve the lightness, thinness, and integration of antennas, which is suitable for the design of wideband multi-beam satellite-borne phased array antennas.

Abstract：This paper introduces an engineering realization of a Ku-band 800 W GaN high linear solid-state power amplifier. A continuous wave output power of 850 W in 750 MHz operation band is realized by the Gysel power divdider and waveguide based power dividing/combining network with 32 GaN MMIC chips. The RF predistortion linearization technology is used to optimize the linearity of the GaN power amplifier, and the third-order intermodulation of the power amplifier is improved by more than 5 dB, which is better than -32 dBc. The power amplifier adopts a forced air cooling scheme with a heat pipe fin radiator, which improves the heat transfer efficiency of the radiator and has good heat dissipation performance. By monitoring the temperature of the power amplifier chip and automatically configuring the speed of the cooling fan, adaptive thermal management of the power amplifier is achieved, which reduces power consumption while reducing product noise. The power amplifier is equipped with comprehensive control and protection functions and has stable technical status. Two power amplifiers form a 1:1 system, which meets the reliability and practicality requirements for engineering use and is suitable for microwave transmission systems in the fields of measurement and control, communication, broadcasting, and television.

Abstract：To improve the flexibility and reliability of soil moisture sensors, a low-cost chipless RFID sensor is designed for wireless monitoring of soil moisture. The sensor consists of three Complementary Split Ring Resonators (CSRR) and two orthogonal broadband circular microstrip patch antennas. Two CSRRs of the same size are closely spaced, which can easily cause coupling between resonators, resulting in more significant changes in resonant frequency in high moisture soil. In addition, the CSRR as a reference resonator is used to eliminate the influence of environmental conditions and improve the reliability of measurement. Two microstrip patch antennas are used for transmitting and receiving signals, achieving wireless sensing function. The Radar Cross Section (RCS) of the sensor with single and double CSRR structures is studied, establishing a linear relationship between soil moisture and the difference in resonance frequency. This relationship has been further confirmed through actual measurements. The experimental results show that the sensor has a sensitivity of 18.2 MHz/%θ at soil moisture ranging from 0% to 12%.

Abstract：In this paper, a novel optimization design scheme is proposed to solve the cascading mismatch problem of sub-circuits in beamforming chips due to parasitic effects. The optimization design scheme proposed in this paper is a design scheme that realizes impedance “pre-mismatch” by introducing the impedance traction effect of adjacent modules and offsetting it with the cascade impedance mismatch. The theory of the “pre-mismatch” technique is provided in the article and a 4-channel X/Ku-band RF transceiver chip has been fabricated to verify the feasibility and effectiveness of this scheme. Compared to conventional designs, the chip operates within the frequency band of 8 GHz~18 GHz, with the receive and transmit average link gains of 6.5 dB and 14 dB, respectively. Both transceiver link gains are increased by more than 2 dB. The transmit link output power is 21 dBm and power-added efficiency is 15.7%，optimized by 1 dB and 9%. The receive link noise figure of 8.72 dB is reduced by 1.2 dB. The maximum phase-shifted root-means-square errors of the transceiver link are 5.25°and 5.12°, with a decrease of 1.75° and 3.17°.

Abstract：To satisfy the future demand for multi-target tracking in hemispherical coverage, a 32-element circular polarized semi-spherical conformal phased array antenna is present in this paper. Hemispherical and cylinder configuration is adopted to meet the communication requirements at low elevation angel. Activate corner domain and different element distributions are compared in detail to decide the optimum performance. Simulated results show that the gain is higher than 13.8 dBi and the gain flatness is less than 1.8 dB within the scanning range of 0°~90°, which indicates this spherical phased array antenna can be applied in the occasions of multi-target tracking in hemispherical coverage.

Abstract：With the continuous development of microelectronic components design capability and process technology, the reliability and life of the device is increasing. Radio Frequency Identification (RFID) tags are characterized by high demand, wide range of applications, and wide geographical (use temperature) span, which puts high demands on the reliability of the product, and it is of great practical significance to study the degradation characteristics at high and low temperatures. Based on Arrhenius theory, this paper proposes a method to quickly calculate the activation energy of electronic tags, to carry out a short time life acceleration test on electronic tags, to predict the life situation through the degradation data of the tag's electric field strength performance, to quickly solve the value of activation energy of the electronic tags, and then to calculate the acceleration factor under different temperature conditions, which provides a theoretical basis for the accelerated test time for electronic tags under different life evaluation standards.

Abstract：In order to meet the power combination requirements of 3 mm band， a novel 8 in 1 high power amplifier， which works at watt level for W band use， is proposed. It achieves module airtightness by utilizing silicon based chips， which is an innovative way for W-band waveguides. The conbiner design is based on the waveguides and the electromagnetic analysis is conducted for the inner structures. High frequency simulating softwares are also used to simulate the power combiner. By comparing the tested results and simulated indicators， this W-band power amplifier based on airtight waveguides can meet all the design requirements.

Abstract：A miniaturized omnidirectional microstrip filter antenna is designed. The antenna is composed of a bandpass filter and a microstrip antenna, which share a ground plane to reduce the size and are connected by gap coupling. The bandpass filter is etched at the feeder position of the microstrip patch antenna, and the frequency selection filter function is introduced. A transverse rectangular patch is added at the front end of the input feeder to achieve good impedance matching of the whole system. Compared with the traditional microstrip antenna, the designed filter antenna introduces the frequency selection filter function without changing the size, and shows high selectivity at the edge of the passband. The simulation and test results show that the impedance bandwidth of the filter antenna is 2.31 GHz~2.56 GHz, and the gain in the passband is flat, the average gain is about 2.1 dBi, and the filter antenna has omnidirectional radiation characteristics in the working frequency band.

Abstract：This paper designs an antenna layout for tethered multi rotor UAV communication system，conducts EMC simulation analysis between antennas using FEKO software, and conducts actual installation and flight test. Simulation and actual measurement indicate that the antenna layout method is suitable for multi rotor UAV communication system.

Abstract：The main signal source is one of the key components of the synchrotron radiation device. It is not only used to generate the highly stable reference signals required by each subsystem of the synchrotron radiation light source, but also used to generate the high-precision working clock required by the control system of the entire device. Generally, one RF signal source is used as the main signal source. But the commercial RF signal source generally has only one output channel, which is far from meeting the needs of the synchrotron radiation device, while the use of traditional power splitters to expand the main signal channel also suffers from amplitude attenuation, accuracy degradation, and inconsistent phase. In order to solve the above problem, the method of extending one channel output of microwave signal source with RF shortcut chip AD9361 has been proposed in the paper.

Abstract：In this paper, according to the needs of airborn ultra-short wave receiver, the system-level design and simulation of RF front-end circuit is carried out by using Advanced Design System（ADS）. By analyzing the performance requirements of ultra-short wave receiver, combined with the main working principle and technical indicators of the receiver, the structure of the dual-conversion superheterodyne receiver is selected as the implementation scheme. The system level simulation model of RF front-end of receiver is established in ADS. The key indicators of RF front-end of the design such as noise figure, sensitivity, gain and intermodulation distortion are designed, analyzed and simulated by ADS. The simulation results show that the RF front-end meets the requirements of the design.

Abstract：In order to realize a high resolution, low phase noise, high spurious rejection, small size and low cost X-band frequency source, and to solve the problems of low frequency resolution of traditional phase-locked loop frequency synthesis and low output frequency of direct digital frequency synthesis, an X-band frequency source design method based on harmonic mixing and small-step phase-locked loop to improve phase noise and frequency resolution is proposed. This method adopts the architecture of harmonic mixing to output coarse step RF signal and HMC830LP6GE phase-locked loop to output fine step mixing loop, reducing the module's discrimination and fixing it to 1∶1.The results show that the X-band frequency source has an output frequency range of 8 GHz~12 GHz, an output power greater than 13 dB, a frequency step of 1 MHz, a spurious rejection better than 60 dBc, and a phase noise better than -115 dBc/Hz@10 kHz. The frequency source has the advantages of small hopping step, small size, low spurious and low phase noise, which can be applied to various applications requiring miniaturized, low phase noise and low spurious X-band frequency source.

Abstract：Due to the high output power of GaAs power amplifier, it is usually used in radar system and other communication systems with pulse system. According to the characteristics of GaAs power amplifier material, its breakdown field strength is low, and under the drain pulse modulation, when the pulse disappears, the current mutation will form voltage overshoot. When the overshoot voltage is high, it is easy to break down the amplifier. In this paper, the generation mechanism of voltage overshoot is introduced, and several measures to improve voltage overshoot are put through theoretical analysis, and the effectiveness of which is verified by actual measurement in GaAs power amplifier.

Abstract：In order to meet the requirements of antenna radiation pattern test of ultrashort wave omnidirectional antenna installed in the airplane, an out-field antenna measurement method of simulating multi flight state is proposed. Out-field measurement system uses the ground fixed equipment to test the small airplane pitch attitude and the unmanned aerial vehicle to test the large airplane pitch attitude.The test principle of unmanned aerial vehicle and the antenna radiation pattern test method under the unmanned aerial vehicle flying around or hovering are proposed. According to the method, the installation performance of antennas at different pitch angles was tested to verify the airplane performance requirements of communication links under different maneuver conditions, providing basis data and test basis for subsequence radio frequency link, radio frequency compatibility and radio frequency stealth analysis.

Abstract：There were two kinds of relations applied in humidity-functional grid asset radio frequency tag: the influence of moisture-absorption nylon on tag dielectric constant, and the influence of tag dielectric constant on tag radio frequency performance. For tag design, it was used that moisture-absorption nylon on package material and narrow bandwidth design on RFID Antenna. Also, it was improved to get center frequency of tag activation sensitivity for read-write handsets. In the test of application simulation, the average absolute difference of relative humidity is 2.0%RH between humidity-functional grid asset radio frequency tag and moisture meter. In this paper, humidity-functional grid asset radio frequency tag achieved to combine sensor function into electronic tag，and nearly can meet the requirement for appropriate measurement accuracy.

Abstract：A miniaturized and reusable receiving front-end applying to satellite communication is designed in the paper, which converts RF signal of 950 MHz to 2 150 MHz to IF by preselected filtering, amplifying and mixing. The design scheme of the circuit is introduced first, and the key indicators are analyzed. The receiving front-end is 105 mm×55 mm×9.5 mm in size. Miniaturization and universal were realized in the paper, which can be reused in various satellite communication devices.

Abstract： Terahertz wireless energy transmission has potential applications in space. This paper introduces the main methods of terahertz generation and reception at present. In view of the phenomenon that terahertz waves can be wirelessly transmitted between subwavelength lithium niobate wafers, the possibility of enhancing the evanescent field on the wafer surface using on-chip microstructures is analyzed, which can increase the distance of terahertz wireless energy transmission between the lithium niobate wafers, providing a feasible scheme for the application of terahertz wireless energy transmission.

Abstract： In this paper, a rectangular waveguide band-pass filter with a center frequency of 140 GHz is realized by using modern Computer Numerical Control (CNC) metal milling technology. The proposed filter is designed based on HFSS and then fabricated by CNC metal milling technology. The measured results agree well with the simulated ones indicating that the filter has excellent performances: the center frequency is 140.2 GHz, the relative bandwidth is 10.1% at 3 dB, the insertion loss is less than 0.5 dB, the in-band return loss is better than 25 dB, and the out-of-band isolation is larger than 30 dB at ±20 GHz away from the center frequency. The results further confirm the feasibility of 140 GHz waveguide band filter fabricated by CNC metal milling technology.

Abstract： This paper proposed a novel 4 in 1 high power airtight amplifier which worked at watt level for 3 mm band power combination use. This design introduced a silicon based structure to achieve airtightness for W-band components, solving the problem of traditional 3 mm band waveguide components being difficult to be airtight. It was designed by using the airtight waveguide structure. The software was also used for simulating the waveguide combiner. Finally, the power amplifier was carefully fabricated and tested. Results show that the final indicators meet design requirements.

Abstract：This paper introduces an engineering realization of an S-band 500 W high phase-stable solid-state power amplifier.According to the engineering requirement,four power chips are used for high powersynthesis,and the solid-state power amplifier with output power＞600 W is realized in the frequency range of 2 025 MHz~2 120 MHz.Under the environment temperature condition of 0℃~30℃，the phase change of 1 W~500 W output power is ＜11.5° by the low additional phase shift design,modular design of diffirent microwave plate units,power back-off and other measures,which achieved the engineering and technical requirement of the centimeter-level TT&C for S-band solid state power amplifier.

Abstract： The orthogonality of different orbital angular momentum (OAM) modes of vortex electromagnetic wave can be used as a new dimension of information muti-use freedom to further improve the communication capacity. A vortex electromagnetic antenna system based on double uniform circular array is designed, which can generate ± 1 and ± 2 four mode vortex electromagnetic signals at the same time. The results of anechoic chamber test and system test show that the designed antenna system has well isolation between different modes, completes the data transmission of four BPSK signals without error code, and achieves significant improvement of system communication capacity.

Abstract：This paper discussed a CQFN shell in 7 mm×7 mm×1.2 mm which was based on HTCC technology for the miniaturization needs of millimeter wave microwave device packaging. In order to solve the problem of electromagnetic leakage during high frequency signal transmission of ceramic shell, the shielding ground hole is designed and optimized from different directions of signal transmission by using HFSS. Through simulation comparison, the shielding relationship between ground hole and electromagnetic signal in different areas is discussed and summarized. The results show that the RF pin could be used in the band from 0.1 GHz～40 GHz. The insertion loss of RF ports is less than 0.65 dB. The VSWR of the package is less than 1.50.

Abstract：A compact and low-cost transceiver front-end module is designed for point-to-point radio communication system in this paper. The transceiver module contains one receive channel, one transmit channel, two groups of LO synthesizers in limited area. The module is implemented using devices with Surface Mount Technology (SMT) and multi-layer PCB for excellent performance, low cost and easy assembly process. This paper firstly introduces the architectures of transceiver front-end, then gives detailed design of key passive and active circuits, and analysis of main performance index. The assembled module is measured, it can transmit more than 20 dBm and receive -60 dBm to -20 dBm RF signal. The output IF signal of receive channel is -10 dBm constantly.

Abstract：This paper proposes a SoC chip clock scheme and designs two layout schemes. By analyzing the causes of electromagnetic interference and judging the simulation results of the isolation degree between signals, the risk of inter-signal interference in the layout scheme can be identified in advance, which will deteriorate the output analog signal quality of SoC chip. In this paper, the simulation results of the isolation degree between signals are used to guide the layout design, and the optimization layout method is given to improve the performance of the isolation degree between signals. The test results show that the simulation results of the two layout design schemes are consistent with the actual results, which verifies the accuracy and reference of the simulation results.

Abstract：To overcome conventional VHF power amplifiers′ shortcomings of bulky size, low efficiency, and EM interferences due to output harmonics, a miniaturized, high power and high efficiency power amplifier working in VHF band is designed by using lumped parameter elements in this paper. In this work, multiple series LC resonators are introduced into the output matching circuit of the power amplifier, with effectively suppressed harmonic components, improved linearity and efficiency, as well as improved electromagnetic compatibility of the power amplifier. Finally, the physical test results show that the saturated output power of the power amplifier is about 44.9 dBm, the saturated power gain is 14 dB, and the power added efficiency is 62%. With its excellent performance, it has good practical engineering application value and can be widely used in aviation, aerospace and other fields.

Abstract：In this paper, a V/UHF integrated antenna suitable for installation on the top of aircraft vertical tail is designed, which realizes the integration of antenna and radome in structure and performance. The integrated and separated V/UHF antennas are studied. The wide-band operating characteristics of the antenna are realized by using the meandering and matching technology. The measured standing wave ratio in the operating frequency band is less than or equal to 2.5. Compared with the separated antenna, the integrated antenna solves the problem of antenna gain reduction caused by the coupling effect between the antenna and the radome. By using the integrated antenna, the gain is increased by about 2 dB in the full band, the weight is reduced by 1.9 kg, and the antenna performance is comprehensively improved.

Abstract：A vertically polarized omnidirectional antenna with high gain is proposed based on the method of series-parallel feeding. Firstly, a printed dipole antenna is used as the basic radiation unit, and then four of the basic radiation units are formed into a series-fed array to improve the antenna gain. Secondly, in order to further increase antenna gain and make the antenna patterns of the series-fed array desensitize to frequency, two four-element series-fed arrays are connected in parallel and fed from the center through a parallel feed network. Finally, the metal support and the microstrip feeding network are symmetrically designed to achieve good feeding and improve the unevenness of the pattern in the horizontal plane. The antenna was fabricated and measured. The experimental results show that the impedance bandwidth of the antenna is 13% and the VSWR≤2 in the frequency range of 7.4 GHz~8.4 GHz. The gain variations in the horizontal plane less than 2.5 dB and the gains are more than 8 dB across the operating band. In addition, the transverse size of the antenna is less than 0.7λ0. The antenna has the advantages of compact structure, convenient processing and excellent performance. It can be used in wide-band, high-gain and wide-angle space coverage communication systems.

Abstract：In order to reduce the phase noise and complexity of the frequency synthesizer, a new design method of low phase noise frequency synthesizer is proposed in this paper. It uses the harmonic generator to generate the high-frequency signal with low phase noise. At the same time, the frequency synthesizer chip LMX2820 integrating the voltage controlled oscillator is used to directly generate the output signal and feedback signal. The feedback signal and low-phase noise high-frequency mixing generate the low-frequency feedback signal, Low phase noise is achieved by reducing the frequency division value through this built-in mixer. The phase noise index of the frequency source of 13.75 GHz~16.25 GHz(excluding 15 GHz) is better than -102 dBc/Hz@1kHz.

Abstract：According to the current requirements for high isolation between frequency bands caused by congested spectrum resources, a new type of miniaturized high suppression waveguide filter is proposed in this paper. Based on traditional waveguide filters, this paper introduces a new CT-type inductive cross-coupling structure between non-adjacent resonators which results in limited transmission zeros in the stopband, and further improves out-of-band rejection, reduces the size of the filter, and reduces the loss introduced by the number of cavities. At the same time, because of the discontinuity of its structure, the mode-matching technique is used to design and optimize the filter. With this method, the design cycle of filter is very short and performance is particularly good.

Abstract：In the background of the operating frequency of 2.4 GHz, based on the designed Doherty power amplifier, an improved Doherty power amplifier with multi-mode switch control and envelope tracking modulation is designed. The tube used in this design is a GaAs transistor NE6510179A from Renesas. The power added efficiency of the designed Doherty peak output(32.0 dBm) reaches 27.2%, and the power added efficiency of the back-off 6 dB is 27.0%. After being improved in cascade with the built envelope tracking model, the new structure can improve the power added efficiency of low output power to a certain extent, and the linearity in the middle and high output power part has been greatly improved.

Abstract：The test of the superconducting quantum computing chip requires dozens or even hundreds of high-frequency microwave signal inputs. The ordinary microwave signal source generally only has 1~2 channels, which is far from meeting the test requirements. If multiple signal sources are integrated to expand the signal channel, it will be not only bulky and expensive, but the synchronization control of the signal source will be also a difficult problem. Aiming at the above problems, based on the power amplifier and power division technology, in this paper，a method of equal-amplitude expansion of one output of the microwave signal source has been proposed, and a signal source equal-amplitude expansion device integrating attenuator, power amplifier and power division module has been designed. Then an experimental platform has been built with microwave signal source, spectrum analyzer, network analyzer and other measuring instruments to carry out experimental research on the performance of the designed signal source expansion device and verify the microwave signal source expansion method based on power amplifier and power division technology. The experimental results show that the proposed method can ensure that the amplitude and frequency of the extended signal are highly consistent with the source signal, and the signal phase of each extended channel can be kept stable for a long time, which meets the requirements of superconducting quantum computing chip testing.

Abstract：Modern transmission systems have put forward higher and higher requirements for the working frequency band and power level of power amplifiers, and the design of power amplifiers based on GaN power devices can meet these new requirements. In this paper, GaN HEMT is used to design the basic power amplifier unit, and the 5-path power synthesizer with asymmetric structure is innovatively used to realize the required power of the whole machine and improve the efficiency of the whole machine. The operating frequency of the power amplifier is 1.65~3 GHz, the measured output power is greater than 500 W(CW), and the power conversion efficiency is greater than 25%. Compared with similar products, the efficiency and volume index have been greatly improved.This product is suitable for high-power system applications, such as EMC testing, electronic countermeasures, etc.

Abstract：A three-frequency coaxial cavity combiner with low passive intermodulation is designed. By designing the tap structure of the common cavity and tuning its relative cavity position and optimizing the height of the steps between the resonant cavities, the intermodulation distortion is reduced, thereby reducing the third-order intermodulation. On the basis of meeting the design specifications, a low-intermodulation triple-frequency combiner based on DCS1800, TD-SCDMA2100, and WLAN2600 was designed, processed and measured. The measurement results satisfy that the third-order intermodulation values of the three frequency bands are less than -172.50 dBc, -169.75 dBc, and -173.30 dBc, respectively, and verify the feasibility of the design.

Abstract：A two-stage low noise amplifier(LNA) with high gain and low power is proposed by analyzing the characteristics of GaAs pHEMT devices. A two-stage structure is used to increase the gain of the low noise amplifier, a shared current structure is presented to reduce the power consumption of the amplifier and the circuit noise at the same time. Input and output matching adopt LC ladder matching network, which has good matching performance. The circuit is simulated using CAD software. The circuit simulation results show that the gain is 27.299 dB, the noise figure is 0.889 dB, S11 and S22 are both less than -10 dB at the center frequency of 12 GHz, and the working bandwidth is 600 MHz. This low-noise amplifier has a certain significance as the front-end design research of the receiver in the 12 GHz frequency band.

Abstract：This paper discussed research on the differences of RF Port simulation and test of X-band power device package which was based on probe test method. After optimizing it with simulation software, samples are produced through HTCC process line, the result of testing the port with GSG probe is much larger than the simulation results. It is analyzed by experimental methods such as control experiment and simulation result reproduction that the difference between S21 simulation and test is due to radiation loss, which affects the signal integrity of the signal in the return path. Insertion loss is greatly reduced after optimizing the structure, which proves that the radiation loss is the cause of the gap. Radiation loss can be effectively solved by electromagnetic shielding. This article can provide a reference for the design, test and practical use of high-power device packages.

Abstract：A circuit topology of a LC series unit based triple-mode bandpass filter featured with hybrid integration and tiny siaze is proposed. The main part of the symmetrical circuit is composed of a “star” structure with four LC series units. It can realize the free adjustment of the two transmission zeroes by adjusting the parameters of the LC series units connected in parallel to the ground. Based on odd-even mode analysis method, this paper presents the comprehensive design method of the proposed filter and develops a triple-mode multiple-zero bandpass filter with miniaturization characteristics by using hybrid integration technology with commercial silicon-based surface mount capacitors. The simulation and test results of the developed filter are in good agreement. The filter has a 3 dB bandwidth of 1.34 GHz at center frequency of 2.6 GHz. The typical insertion loss of the filter is 1.6 dB. The upper stopband attenuation higher than 30 dB is 4~12 GHz. It occupies only 3.2 mm×1.9 mm(0.03λ0×0.02λ0).

Abstract：When the electromagnetic signal penetrates the medium, its signal intensity will be reduced due to the scattering of electromagnetic waves and other reasons, and even change the polarity of electromagnetic waves. In order to measure the influence of electric charge on electromagnetic wave attenuation, this paper designed an electromagnetic wave attenuation experiment with dielectric plate, and selected typical dielectric plates such as PP plate, PVC plate and PMMA plate to conduct an experimental study on electromagnetic wave signal attenuation. The results show that the attenuation of electromagnetic wave is enhanced when the dielectric plate is charged, and the attenuation is enhanced with the increase of electric quantity.

Abstract：A miniaturized ultra-wideband receiver module is designed for electronic reconnaissance system in this paper. The receiver module contains two down-converter receiving channels, two LO synthesizers and a self-checking circuit in limited area. The module is of superheterodyne with twice frequency conversion by millimeter wave local oscillator，and the miniaturized circuits based on a series of multi-function MMICs are designed. To reduce the thickness and lateral dimensions，the through holes between microwave circuits and control circuits are adopted for interconnection. To realize self-calibration function，self-calibration synthesizer generates a signal，and then the ADC collects the voltage of DLVA，finally the gain and the consistence of two receiving channel are optimized based on adjusting the digital attenuators. Through above steps, the receiver module is easily manufactured, thus batch production efficiency is improved.

Abstract：A vertical interconnection structure based on a stack of multi-layer silicon interposer boards is designed. The simulation results of the vertical interconnection structure of the two interlayer structure not considering and considering the SiO2 layer on the silicon surface were compared in the DC-60 GHz frequency band. The existence of the SiO2 layer has an impact on the radio frequency performance such as resonant frequency and impedance. The parameters of the latter vertical interconnection structure are optimized, its RF transmission performance is good, and the return loss S11 is less than -30 dB when the frequency is below 40 GHz, the overall S11 is less than -15 dB below 60 GHz, and the insertion loss S12 is greater than -0.32 dB below 50 GHz. This paper simulates and analyzes the influence of the thickness of SiO2 insulation layer on the silicon surface on the transmission performance of the radio frequency signal. The results show that appropriately increasing thickness of SiO2 insulation layer can help optimize the performance of the vertical interconnection structure.

Abstract：In response to the requirements of satellite L-band communication and forwarding systems, a novel type of satellite-borne L-band broadband high-gain circularly polarized microstrip antenna is designed. The microstrip antenna adopts a side-fed feeding method as a whole, adopts an H-shaped slot coupling feeding method to achieve a wide frequency band, and uses a Wilkinson phase shift power splitter to achieve the phase difference between the two signals to meet the circular polarization, and add the antenna back reflector and foam layer between the boards to increase gain and stabilize the structure. Through the analysis of electromagnetic simulation software, it can be obtained that the gain is 8.3 dBi at the center frequency point of 1.45 GHz, the axial ratio is 0.7 dB, the relative bandwidth is 23.5% when the gain is greater than 7.5 dBi and the return loss is less than -10 dB. The actual measurement results of the antenna processing are basically consistent with the simulation results, which have certain guiding significance for the design of the L-band wireless communication system.

Abstract：In order to realize the four-way parallel switching circuit of X-band and improve the isolation between channels effectively, a high isolation switch scheme of X-band based on new microassembly technology was proposed. While analyzing the performance of the Single Pole Double Throw(SPDT) switch and designing corresponding control circuit according to indexes, at the same time, design of cavity in terms of structure and laminated structure of composite multilayer board ensured the isolation between the four switches. Softwares were used to model, simulate and then measure the isolation degree between the channels to decrease the cavity effect. After optimization, the isolation degree of the port could be controlled above 50 dB at the center frequency. The X-band switch component was made by means of microassembly technology, and the advantages of the component performance were verified by comparing the measured data with the simulation results. The design method is unique, practical and suitable for application in practical projects.

Abstract：The diplexer and the power divider are two important components in the communication system. In order to reduce the size of the communication system, in this paper, the power divider is integrated into the diplexer to form a diplex-power divider. Compared with the general diplexer, it can realize the output of two-port power division output. The diplex-power divider is mainly composed of rectangular ridge waveguide transition, ridge waveguide band pass filter and ridge waveguide powerdivider. The ridge waveguide bandpass filter based on the evanescent mode has the advantages of low insertion loss, compact structure, wide passband and stopband. The HFSS is used for modeling and simulation optimization. The simulation results show that at 71～76 GHz, the return loss is greater than 12.9 dB, S32 and S42 are basically maintained at around -3.8 dB;at 81～86 GHz, the return loss is greater than 12.5 dB, S31 and S41 are basically maintained at around -3.85 dB, the isolation between channels is greater than 43.2 dB, and the amplitude of the two output ports are basically the same. The actual test results are in good agreement with the simulation results.

Abstract：Aiming at the problem of cruise missile penetration trajectory planning under the threat of dynamic early of warning aircraft radar, an improved deep reinforcement learning intelligent trajectory planning method is proposed. Firstly, aiming at the penetration mission of cruise missiles facing early warning threats, a typical combat scenario is constructed, and a prediction formula of radar detection probability of early warning aircraft is given. On this basis, a reward function that introduces dynamic early warning threats is designed, and the deep deterministic policy gradient algorithm(DDPG) is used to explore the intelligent penetration of cruise missiles. And then, in response to the poor exploration ability of the traditional DDPG algorithm that explores the uncorrelated timing of noise, Ornstein-Uhlenbeck noise is introduced to improve the training efficiency of the algorithm. The simulation results show that the improved DDPG algorithm training convergence time is shorter.

Abstract：According to RAM-C experimental data, an inversion modeling method for plasma sheath is presented, which provides a new way to construct the three-dimensional(3D) local transmission channel from one-dimensional(1D) sheath data. Then, the ray tracing method is used to study the energy transmission interference of the plasma sheath to some frequency points at L and S bands. Finally, the investigation shows some new propagation behaviors，such as the transmission convergence effect, where the EM energy is locally transmitted in a specific direction. The results can further promote the understanding on sheath interference, and provide a new modeling method for the actual physical modeling of related problems.

Abstract：A spaceborne phased array antenna with high-gain, circular polarization and wide-angle is designed to meet the requirements of large range data transmission of X-band communication system. The antenna array element is fed by the bottom feed, the circular-polarization is realized by the angle cutting technology and the miniaturization is realized by the slot technology. The array is arranged in staggered layers, so that the radiation performance is the best. Through reasonable layout and optimization design of transmitting module, beam control module and power module, the beam can be changed within 0～60° off-axis angle and 0～360° azimuth angle. The test results of this machine are good after machining, which has a certain guiding significance for the design of X band communication system, especially the phased array antenna.

Abstract：A fully-integrated dual-mode low-noise RF receiver front-end for the 2.3 GHz～2.7 GHz band was presented based on a GaAs pHEMT technology. The receiver front-end consists of a single-pole double-throw(SPDT) transmit-receive switch and a low-noise amplifier(LNA)with bypass mode. The cascode common-source structure with inductive degeneration topology is adopted to achieve the LNA.The SPDT switch is embedded into the input matching network as a concurrent design to realize high Q matching network with minimum components for low noise, high gain and superior input return loss matching. Concurrent design of multiple switches for Bypass function is utilized to attenuate the high input power transmissions. The measurement results show that the presented FEM exhibits low noise figure of 1.53～1.64 dB and gain of 18.1～19.2 dB for 2.3～2.7 GHz frequency range in the high-gain LNA mode. At 2.5 GHz, the tested input 1 dB compression point at 2.5 GHz is -1.5 dBm. The insertion loss in Bypass mode typically varies from 6 to 7 dB in the operation frequency bands.

Abstract：In this paper, a Ka-band frequency source for miniaturization of rendezvous parameter detection unit is designed by using PLL and multiple frequency multiplication. The output frequency of the frequency source is 36 GHz and the output power is higher than 15 dBm. In this design, the mathematical modeling method is used to model each part of the PLL, and then the transfer function of the system is obtained. Through the analysis of the system function of the closed-loop system, the system parameters that can make the system work stably are obtained. Finally, dies are fabricated on the substrate and cavity of RO4350 and RO5880 in the form of micro assembly, and then be tested. The test results show that the stable working frequency source can be obtained by using mathematical modeling.

Abstract：Radiation interference is one of the bottlenecks that restrict the high frequency and miniaturization of power products. Based on the simulation idea of field circuit coupling, the electromagnetic field finite element model of MOSFET and the equivalent high frequency circuit model of high frequency transformer are established. Combined with the PCB network parameters extracted from SIwave,the board level radiation interference of a 5 W output flyback converter is co-simulated, and the influence of two high frequency transformer models on the far-field simulation results is compared. The experimental results show that the simulation results of 3 m far-field within 230 MHz are in good agreement with the measured results, which verifies the correctness of the simulation method, and the simplified two capacitance model of transformer has wider applicability; the obtained near-field electromagnetic field distribution shows that MOSFET is the main source of electric field radiation, and the rectifier diode at the secondary side of transformer is the main source of magnetic field radiation.

Abstract：Silicon-based radio frequency field effect transistors have the advantages of excellent linearity, simple drive circuit, fast switching speed, excellent thermal stability, no secondary breakdown, etc., and have broad application prospects in HF, VHF and UHF bands. In view of the application requirements of the RF field effect transistors with broadband, high gain and high efficiency, based on the standard planar MOS process, the split gate structure was adopted and a silicon-based RF vertical double-diffused metal oxide semiconductor field effect transistor with working voltage of 28 V was developed by optimizing the structure and process parameters. In the frequency range from 30 MHz to 90 MHz, the device can achieve small signal gain greater than 19 dB, the continuous wave output power can reach 87 W at the frequency of 60 MHz, the power added efficiency up to 72.4%, has excellent radio frequency performance.

Abstract：Two strong signals would produce third order intermodulation components which would interfere with the work of the receiver when they are received by the receiver. In order to reduce the interference, thus increasing spurious free dynamic range of the receiver, a receiver channel with large dynamic range is proposed. By properly distributing the gain of the channel and suitable component selection, the 3rd-order Output Intercept Point(OIP3) is achieved to 45 dBm. The multichip module(MCM) technology is applied to establish the hardware of the receiver. The receiver is tested by an improved test method, verifying the its excellent dynamic range.

Abstract：Many handheld terminal devices require a light and compact receiving and transmitting antenna. FPC antennas are popular among designers because of their light weight and thin thickness. In order to obtain an antenna with suitable size, bandwidth and gain, an FPC soft material is used as an integrated platform, and the transmission line and antenna are used as an integrated design. While maintaining the size of the antenna, the energy coupling of radiating unit is enhanced by adding coupling branches，which effectively improves bandwidth and gain. The integrated design of transmission line and antenna can effectively use the antenna space and improve the port characteristics. Through simulation and actual testing, the antenna bandwidth meets 470 MHz~510 MHz, S11<-10 dB. S11<-12 dB at 490 MHz, the effective gain is 0 dBi.

Abstract：According to the definition of noise figure，this paper deduces the cascade noise figure formula of receivers with mixers. By using this formula，it is easy to calculate and analysis the system noise figure affected by the device noise figure, gain and filter image rejection. The position of image rejection filter behind the low noise amplifier needs place as close as to the mixer. The gain before the filter and filter image rejection needs high enough, at least greater than 20 dB. Through the proper design and image rejection, the noise figure of the receiver which has two-stages, three-stages frequency conversion will decrease close to 6 dB and 9 dB, than when the image noise do not be rejected at all.

Abstract：The RF microsystem is the future development trend of electronic equipment miniaturization, and the ball grid array(BGA) is one of its common implementation forms. Because the BGA package cannot be measured by being connected to a vector network analyzer, the testing technology of the RF BGA package is studied. A test fixture that can be applied to the RF BGA package in DC-40 GHz is designed, and a series of cal-kits are designed for it, which solves the test problem for RF BGA package. The simulation results show that the return loss of the test fixture at work is more than 18 dB in DC-40 GHz. The return loss of the designed open-circuit cal-kit is less than 0.88 dB. The insertion loss of the through cal-kit and the line cal-kit are both less than 1.1 dB. The simulation results meet the designing requirements of calibration. The product has good electrical contact, and is solder-free, reusable, easy to process, and convenient to take and unload. It is universal for standard size BGA package.

Abstract：This paper introduces a design of RF Switchbox for RFID-OTA test system which can be programmed switching. According to the requirements of RFID and OTA test system for multi-band testing and path calibration，through reasonable structure design and system layout design, the programmable RF-Path switched of RF switchbox in the RFID-OTA test system is realized, which enables the test system to automatically complete the performance test and test path calibration of products in different frequency bands.

Abstract：In the face of the development of miniaturization and compactness of chipless RFID tags, and in order to reduce the cost of traditional RFID tags, this paper proposes a compact, polarization insensitive, passive chip less RFID tag based on 1/4 ring resonant unit. It has a high coding density of 4.39 bit/cm2 in the frequency range of 6 GHz～11.5 GHz. The pole of the tag is extracted by Matrix Pencil Method(MPM). Compared with the simulation data and the algorithm extraction data, the designed tag meets the requirements of identification accuracy and has good data coding performance.

Abstract：In order to meet the needs of microwave devices for high-resolution, non-destructive microwave vector near-field measurement, an all-optical microwave near-field vector measurement technique based on diamond nitrogen-vacancy(NV) centers is proposed. Using the sensitivity of NV centers to the circularly polarized electromagnetic field, the tapered optical fiber probe with diamond NV center is used as the sensor to measure the optical detection magnetic resonance(ODMR) spectrum with 8 peaks in the external static magnetic field environment, and the distribution of electromagnetic field components in different NV directions on the surface of microwave device is measured under the corresponding microwave frequency of each ODMR spectrum peak. The results of microwave near-field vector measurement are obtained. Finally, 3 μm diamond particles are used for near-field vector imaging of microstrip antenna with resonance frequency of 2.87 GHz. The experimental results show the effectiveness of the method, which can be widely used in chip electromagnetic compatibility(EMC) test, integrated microwave chip failure analysis, digital circuit signal integrity analysis, etc.

Abstract：In this paper, a low-cost, tiled millimeter wave active phased array antenna(APAA) is presented. The APAA integrates CMOS multi-function chips, GaAs chips, antenna array and power division network on a microwave multilayer print circuit board by a three-dimensional integration technology, then the height of the APAA has sharply decrease. The RF part of the APAA is interconnected with the frequency conversion module, wave control module and power supply module through the vertical interconnection of radio frequency and low frequency pins. The measured results show that the APPA can achieve 7.7% bandwidth in a scanning range of ± 25° in all planes in Ka-band, and the gain changes smoothly in the scanning range, less than 1 dB gain variation, and the sidelobe level is better than 14.5 dB. The APPA has low profile of 52 mm, ERIP is larger than 66 dBm, G/T is better than 7.5 dB/K, and the transceiver switch time is less than 150 ns. In summary, this tiled active APAA has characteristics of high integration, miniaturization and low cost，and has high engineering application value.

Abstract：An design of a 5 W solid-state power amplifier in Q band by using antipodal finline-to-microstrip transition was presented.The four-way waveguide T-junction and antipodal finline-to-microstrip is designed and simulated through the high frequency structure simulator(HFSS).The simulation result show that the insert loss of four-way T-junction is less than 0.1 dB and the insert loss of antipodal finline-to-microstrip is less than 0.1 dB. The four-way power combiner/divider is made and test. The test result shows that the insert loss of four-way power combiner/divider is less than 2 dB in the the frequency range of 43.5 GHz~45.5 GHz, and the synthesis efficiency is more than 80%. A 2 Watt level die was selected for the amplifier module and the gold boding wire is connected the die to the microstrip. The test result shows that saturation power is more than 5.7 W,gain is more than 10.5 dB and efficiency is more than 9.5% in the frequency range of 43.5 GHz~45.5 GHz. This structure has a very broad application prospect in the field of millimeter wave power amplifier.

Abstract：A mu-zero resonance(MZR) resonator is etched in the patch of a printed monopole antenna. The MZR resonator generates a new resonance. As the MZR resonance is lower than the monopole and the resonances merge with each other, size reduction and bandwidth enhancement were obtained. A prototype was designed and fabricated. The test results show that the impedance bandwidth of the MRZ-Loaded monopole is extend to lower frequency remarkably. Because of the small electric structure of the antenna, the omnidirectional radiation and the beam pointing stability is well guaranteed. A microstrip line based model was built to analyze the MZR resonator antenna.

Abstract：In order to greatly improve the system capacity in local hotspots, the wireless communication infrastructure that can support high-frequency and wideband operation is required for ultra-dense networking. A 4.8～5.0 GHz three-stage high-gain and large-output power amplifier is designed using GaAs heterojunction bipolar transistor(HBT) process to be targeted for 5G microcells. The pseudo-differential structure is adopted to suppress the influence of ground parasitic inductance, while the conversion between single-ended and differential pairs is completed by off-chip low-loss LC balun. In conjunction with active adaptive bias network and RC negative feedback circuit, meanwhile applying the methods of wideband matching and predistortion compensation, ADS(Advanced Design System) simulations verified that the proposed power amplifier can achieve 35.8 dB power gain with 33.5% peak power-added efficiency at a center frequency of 4.9 GHz, and deliver not less than 35 dBm saturated output power in the operating band, which can meet the requirements of seamless coverage of network signals in typical application scenarios.

Abstract：Combined with the finite difference time domain, physical optics and ray tracing in inhomogeneous media, the influence of the electric propulsion plume on the electromagnetic transmission environment around the satellite is studied, and the simulation software for the electromagnetic effect of the propulsion plume is developed. Because the algorithm uses a computational framework based both on the low-frequency algorithm and high-frequency algorithm, it can provide a broadband solution for the analysis of such problems. Finally, using C# platform, a convenient operation interface is obtained, which can provide an effective numerical simulation method for the analysis of the local electromagnetic environment of satellite, and make up for some deficiencies in this field.

Abstract：GaN, as the new generation semiconductor material, has much wider forbidden bandwidth, higher breakdown voltage, more excellent thermal stability than Si and GaAs, and thus is widely used in the broadband power amplifier design. Based on two GaN RF dies of CREE company are cascaded and the matching circuit is a mixture of centralized and distributed components, a broadband power amplifier is designed in the 20 MHz～520 MHz frequency by using feedback technology to improve band width, RC parallel network to improve stability and micro-strip hybrid matching circuit. The die model and matching circuit are optimized and debugged by the ADS software. In the 20 MHz～520 MHz frequency band, the saturation output power of this power amplifier is more than 9 W, the gain is more than 29.5 dB, the drain efficiency is higher than 40% and the gain flatness is ±0.7 dB.

Abstract：A new research and design method based on CBB for integrated wideband communication radar superheterodyne receivers is proposed in this paper, aiming to provide a fast and efficient design method for multi-purpose receiver design. Seven common basic blocks have been established in the proposed method. Each block is responsible for part of the functions of a receiver. Respective product libraries for the seven common basic blocks have been built through serial development and production based on their respective characteristics. During a superheterodyne receiver design, we can just select several proper CBB from the library according to the technical requirements and combine them to complete the corresponding receiver. This can simplify system engineering, reduce repetitive development, shorten the development cycle, improve product maturity and facilitate testing and maintenance of the equipment.

Abstract：Chokes in integrated circuits and system in packages are used between power grids and active devices. It can maintain DC biasing and RF isolation of active circuit, and its topological structure should match power network structure. In this paper, a wedge-shaped choke is proposed to solve the problem of complicated shape, complicated design procedure and difficulty in embedding power network of conventional RF choke. Its topological structure is similar to strip power grid. The choke consists of an outer arm and an internal rail whose location can be determined by stop-band frequency. The choke exhibits high input impedance in the stop-band once the flare angle of outer arms is at an appropriate value. The design idea is validated by HFSS electromagnetic field simulation. The prototype of the choke is fabricated using printed circuit technology. Both simulation and measurement prove the effectiveness of the choke. Its structure and design process are simple, and it can be easily embedded in IC chip. Even digital engineers can easily implement it.

Abstract：Aiming at the design requirements of miniaturization and modularization of X-band multi-wave phased array components, this paper designs a SiP receiving module combining multi-chip module technology and microwave millimeter wave high-density vertical interconnection technology. Using HFSS to optimize the design of the semi-open quasi-coaxial structure, and using the three-dimensional layout of the double sided multi-cavity, the ML-SL-SL-CPWG and ML-SL-CPWG were designed as the no-lead pins for the X-band receiving SiP module. Receiver component gain≥32.8 dB, noise figure≤3.0 dB. And the module volume is only 12.5 mm×15 mm×5.4 mm，which is 63% area smaller and 76% volume smaller than the original two-dimensional planar system. At the same time, modular design has great advantages in system application.

Abstract：The plane wave generator(PWG) is a novel measurement system for 5G over the air(OTA) testing. A quasi plane wave in the near-filed is synthesized by exciting the antenna elements in the PWG array gracefully. The PWG system does not only meet the requirements of traditional passive antenna measurement, the radio frequency(RF) parameters as well as system performance of the base station(BS) can be accurately measured in the same system. The application superiority of the PWG system is the spacing saving ability, resulting in a significant cost saving, which prompt it to become an alternative solution of the traditional conducted measurement technology. In this paper, the developing history, the design process and typical scenarios in 5G application of the PWG system are proposed.

Abstract：Microstrip line and coaxial are the two common transmission lines in microwave systems. The common interconnection method between the two transmission lines at the low frequency band is direct soldering. The coaxial inner conductor is soldered on the metal strip line of the microstrip line. The outer conductor is mounted on the ground plane of the microstrip line. This connection has little effect on the transmission of microwave signals in the low frequency band. In the millimeter wave band, this connection will result in an increase loss of the millimeter-wave signal. Therefore, a millimeter-wave band microstrip coaxial transition structure is designed. This transition structure adds a transition hole structure between the microstrip line and the coaxial, which can effectively reduce the voltage standing wave ratio and insertion loss of the microstrip-to-coaxial transition structure, and improve the performance of the overall system.

Abstract：As one of the core components of the RF power system, the RF power source has a fixed frequency and low conversion efficiency, which has become a bottleneck restricting the development of the RF power system. Aiming at this problem, a design scheme for freely switching the RF power source between dual frequency operation modes is proposed. Direct Digital Synthesizer is used as the RF signal source. The MOSFTE producted by IXYS Company of Germany is used to achieve the amplification of small signals, which improves conversion efficiency and the stability of the output frequency. The method of parallel inductors reduces power loss during switching time. Switching the frequency selection network with a digital-controlled switch achieves adaptation of the system at dual frequencies. At the same time, Multisim simulation is carried out on the proposed scheme and theory. After actual testing, the RF power source can achieve dual frequency selection output of 13.56 MHz and 27.12 MHz at 300 W, and the conversion efficiency can reach 90.1%.

Abstract：A miniaturized ultra-wideband receiving front-end applyingto radio reconnaissance is designed in this paper,which converts RF signal of 0.1 GHz to 18 GHz to intermediate frequency(IF) by preselected filtering, amplifying, mixing, bandwidth filtering and gain controlling. The design scheme of the circuit is introduced first, and the key indicators are analyzed and designed. The front-end is 119 mm×61 mm×9.5 mm in size, with operating frequency of 0.1 GHz~18 GHz and typical gain of 35 dB，which can also be adjusted from 30 dB to 40 dB according to project requirements.

Abstract：In order to solve the difficulty of high density interconnection of multi-chip modules, a kind of microwave interconnection structure based on composite multi-layer printed circuit board(PCB) technology is designed.The optimized multi-layer interconnected structure is only 0.1 dB larger than the insertion loss of ideal microstrip in the 10 GHz～20 GHz, and the VSWR is 0.3. In the 30 GHz～40 GHz range, it is only 0.3 dB larger than the insertion loss of the ideal microstrip, and the VSWR is 0.4, which has good microwave characteristics. This structure has the advantages of simple design and low cost, which can solve the problem of high density interconnection of components.

Abstract：The radar scattering cross(RCS) which represents the echo strength of the target under the incidence wave is one of the most important concepts in the radar stealth. With the characteristics of small(low RCS), slow(low flight speed) and low(low flight height), the RCS of the unmanned aerial vehicle(UAV) in complex electromagnetic environments are affected by the geography, meteorology, non-cooperative radar radiation source and so on. Based upon such conditions, the RCS of the UAV in the complex electromagnetic environments and the influence of the radar echo are presented in this paper. Meanwhile, the research progress on the RCS of the UAV in the complex electromagnetic environments are introduced.

Abstract：Facing on the contradiction between the coding capacity and the tag size in the design of chipless tags, a new chipless tag structure is proposed. The tag is composed of a substrate-integrated waveguide and a complementary split ring on the surface patch. The complementary split ring contains nested inner ring and outer ring. The resonance frequency of the tag can be tuned by adjusting the opening angle of the inner and outer ring of the complementary split ring, in which the outer ring is responsible for a wide range of frequency coarse tuning, and the inner ring is used for a small range of frequency tuning. The tag operates in the frequency range of 4 GHz to 6 GHz, the size is 25 mm×15 mm, and the coding density is as high as 4.86 bit/cm2. The radar cross section curve of the tag is obtained through simulation, and the consistency with the theoretical analysis is verified. Compared with the traditional chipless tag, the structure can improve the coding capacity without increasing the size of the tag, while the substrate-integrated waveguide provides high selectivity for the tag, which keeps the tag with high spectral resolution.

Abstract：Although the uniform theory of diffraction(UTD) could be theoretically applied to arbitrarily-shaped convex objects modeled by non-uniform rational b-splines(NURBS), one of the great challenges in calculation of the UTD surface diffracted fields is the difficulty in determining the geodesic paths along which the creeping waves propagate on arbitrarily-shaped NURBS surfaces. In differential geometry, geodesic paths satisfy geodesic differential equation(GDE). Hence, in this paper, a general and efficient adaptive variable step Euler method is introduced for solving the GDE on arbitrarily-shaped NURBS surfaces. In contrast with conventional Euler method, the proposed method employs a shape factor(SF) ξ to efficiently enhance the accuracy of tracing, and extends the application of UTD for practical engineering. The validity and usefulness of the algorithm can be verified by the numerical results.

Abstract：With the rapid development of modern communication technology, there comes great demand of multi-frequency and broadband antennas of compact size. It is also urgent to solve the problem of the shortage of spectrum resources and low utilization of spectrum. In this paper, the new spectrum reuse resources of orbital angular momentum(OAM) are combined with ultra-wideband antenna technology, a kind of ultra-wideband OAM antenna is designed. The simulation results show that the working band of OAM antenna covers Ku, K and Ka multiple frequency bands, and multiple modes of OAM beam can be generated in the microwave section of the high frequency. The OAM beams of various modes have good rotation and symmetry, and the characteristics of different OAM mode beams are analyzed. Finally, it is found that the same mode OAM beam is generated at different frequency points at different frequency bands, which energy concentration is basically consistent. This indicates the feasibility and effectiveness of the OAM antenna.

Abstract：A miniaturized microstrip bandpass filter is presented. The proposed filter consists of four folded stepped-impedance resonators. As compared with its corresponding conventional uniform-impedance resonator or stepped-impedance resonator counterparts, the folded stepped-impedance resonator can save nearly 50% circuit size since it takes full advantage of its occupied circuit area. Owing to the simultaneous existence of the adjacent and nonadjacent coupling in the proposed bandpass filter, three different cross-coupling path-pairs can be established to generate three different transmission zeros, which can improve the selectivity performance and width of stopband of the proposed filter effectively. Measured results of the prototyped filter agree with its simulations quite well. Meanwhile, the prototyped filter performs roll-off speed of 100 dB/GHz, and its upper stopband can be up to 11.5 GHz with relative rejection over 33 dBc. Compared with some similar works, the prototyped filter achieves electrical-size-reduction of 23%, which can satisfy the requirements of miniaturization of microwave circuits.

Abstract：New requirements of RF test for 5G mobile communication are presented in this paper. Low test cost and small uncertainty of 5G RF indoor test methods are highlighted, which include indoor microwave far field simulation method, indoor real application scene simulation method and passive intermodulation(PIM) testing methods. This paper also emphases on key technologies including planar wave generator based on antenna array and 5G channel model.

Abstract：A 1.5 GHz～2.5 GHz analog complex correlator using “add and square” scheme was designed and implemented for passive millimeter-wave imaging applications. A digital gain and offset control scheme was adopted. The results of single frequency test show that the output amplitude variation is less than 1.5 dB, and the equivalent correlation bandwidth is 0.905 GHz. Meanwhile, the results of broadband noise measurement show that the correlator phase accuracy is better than 2.5°. At last, an experiment under low SNR environment is carried out to evaluate the influence on the signal-to-noise ratio(SNR) brought by different input power. The results show that in the range of -20~-10 dBm, SNR becomes higher as input power increases and SNR is 13 dB when input power reaches -13 dBm.

Abstract：Based on quadrature exciting and receiving technologies, a set of transmitting and receiving bird cage coil was designed and manufactured. The resonance can reach 400 MHz and imaging of atom H can also be attained on the 9.4 T imaging system. The workbench test result indicated that the bird cage coil reached a high Q value and the isolation of the two channels was 20 dB. At the same time, the sample test was conducted whose results showed that the image was of high uniformity, image SNR and clearness. Featuring simple design process and low cost, the birdcage coil has the model significance to the design and manufacturing of RF coils in ultra-high magnetic field imaging.

Abstract：In view of the requirements of multiple frequency bands working systems, such as mobile communication system and the Radio Frequency Identification(RFID) system, a new divisive growing type fractal structure is proposed. The PI type quadrilateral snowflake structure is used to going on divisive growing type fractal iterative calculation, with which implements a highly integrated equivalent composite radiation edge, and designed a divisive growing type fractal microstrip antenna. This antenna can cover the 900 MHz frequency band and 1.9 GHz frequency band of mobile communication system, 2.45 GHz frequency band of the RFID system at the same time. The return loss minimum values of three working frequency bands are all below -20 dB, and the working bandwidth of three working frequency bands are all better than 0.2 GHz. The radiation characteristics of antenna are all have high stability in three working frequency bands. This novel antenna successfully realizes the compatible of mobile communication system and the RFID system, and ready for appalling to mobile communication and remote identification and payment system.

Abstract：In this paper, a GaN wideband power amplifier is designed. A wideband power amplifier of 2～6 GHz based on CREE CGHV60040D chip model is designed, with modeling and electromagnetic field simulation of bonding wire and micro-strip，designing and optimizing load impedance matching in simulation software with the principle of optimal load matching network. The pulse signal measured results show that the broadband power amplifier module has a good performance in the wide band of 1.8～5.5 GHz, thegain is 10～13 dB, the output power is above 43 dBm, and the power added efficiency(PAE) is above 40%.

Abstract：Radio frequency(RF) and microwave makes effective supplement to other security detection methods due to its unique characteristics. This benefit brings rapid progress of research in the field of security application, and has played an important role in the field of import and export of human security, small UAV capture, border security, electronic radio frequency identification(RFID) and other occasions. In today′s more and more complex security environment, RF and microwave technology has become an indispensable part in protecting public safety.